1. Field of the Invention
The present invention relates to an assembly for controlling a stopper belonging to a continuous casting installation, as well as to a continuous casting installation provided with such a control assembly.
2. Brief Description of the Related Art
The first step of a continuous casting operation conventionally consists in pouring molten metal into a basin, also called tundish, from a ladle. This tundish is, in addition, provided with a stopper.
When the molten metal has reached a given level in the tundish, it is then poured into a mould, under the effect of a movement of release of the stopper. This then initiates a phase of filling of the mould until a given reference level is reached.
According to a first variant, it is firstly known to start up this continuous casting manually. However, in addition to its relative lack of repetitivity, this solution requires the intervention of at least one operator.
In order to overcome these drawbacks, it has been proposed to effect the afore-mentioned start up automatically. In this spirit, the stopper is driven by means of a control assembly, also called actuator, in a stroke guaranteeing a satisfactory phase of filling of the mould.
Such an arrangement is known in particular from EP-A-0 734 801. The assembly for controlling the stopper, described in this document, comprises a drive shaft free to slide in a movement of translation with respect to a guiding assembly.
This drive shaft is fast with an intermediate arm directly supporting the stopper. A rotary servo-motor is also provided, as well as a device for converting the rotational movement, imparted by this motor, into a movement of translation of the shaft.
More precisely, this movement converting device is in the form of a screw jack. It should, moreover, be noted that the motor is offset laterally with respect to the drive shaft, with reference to the principal direction of the latter.
However, this known solution presents certain drawbacks.
For example, the assembly controlling the stopper presents relatively large dimensions. Furthermore, it is necessary to provide as many motors as guiding members, which is disadvantageous from the economic standpoint.
It is an object of the present invention to overcome the different drawbacks of the prior art set forth hereinabove.